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Driftsonde - NCAR
The Driftsonde will be available in 2009 after the Major THORPEX Research Projects, T-PARC and Concordiasi are completed (i.e. end of 2008).
The Driftsonde is not presently in the NSF Deployment Pool and therefore deployment costs are not funded by the NSF. To request the Driftsonde for a research project see Responsible Contact below. Responsible Contact: Contact name: Dr. Steve Cohn - Facility Manager Institution: In-Situ Sensing Facility, Earth Observing Laboratory/NCAR Address: Foothills Laboratory 3450 Mitchell Lane Boulder, CO 80301 Telephone: 303-497-8826 E-mail address: cohn@ucar.edu URL: www.eol.ucar.edu Relationship of submitter to contact:
Surface Remote
The original motivation for developing a driftsonde observing system was to support research associated with the WMO’s THORPEX program. The major goal for driftsonde is to develop a low-cost measurement system that can produce vertical profiles of in-situ measurements in forecast sensitive regions (i.e., targeted areas where numerical models predict that such measurements would improve the prediction of high impact weather events) as well as make soundings that will fill critical gaps in data coverage over oceanic and remote arctic and continental regions. Forecast sensitive regions that would be targeted for driftsondes are (1) relatively void of in-situ measurements from radiosondes and commercial aircraft, (2) covered with extensive cloud shields so that satellite measurements are limited. The across the ocean driftsonde flights will provide synoptic-scale high-vertical-resolution atmospheric profiles made by GPS dropsondes that would be difficult or impossible to obtain by deployment of aircraft alone. The targeting ability of the driftsonde will be accomplished, when possible, by controlling the launch location, the launch time of the balloon, the time of dropsonde deployment and to a limited extent the initial mission altitude (i.e. the wind field). The GPS dropsonde currently in use measures wind, temperature, pressure and relative humidity. The driftsonde system consists of a low-cost zero-pressure polyethylene balloon that has a duration of approximately five to seven days or a moderate duration super pressure balloon that can fly for weeks or even months, either type balloon has an attached NCAR gondola. Housed in the gondola are the system electronics which includes an embedded computer, a GPS navigation system, flight level PTH sensors, a ballast control system, a battery power system, an Iridium satellite two-way communication system, and up to about 60 dropsonde tubes for the new MIST dropsonde. Each of the newly developed small, lightweight Miniature In-situ Sounding Technology (MIST) dropsondes can be dropped at predetermined times by computer or on command through a satellite link. The driftsonde balloons can fly at an altitude of 16 kilometers up to 30 kilometers (100 - 10 hPa) in the lower stratosphere or upper troposphere above the clouds and weather systems. Three sizes of zero pressure (zp) balloons have been developed to date and one size super pressure (sp) balloon: (1) a 100 hPa or 363 cu meter zp balloon, (2) a 50 hPa or 1200 cu meter zp balloon, (3) a 10 hPa or 10,000 cu meter zp balloon and (4) a 50 hPa 12 meter diameter sp French (CNES) balloon. A THORPEX driftsonde demonstration project with the French (CNES) for the African Monsoon experiment (AMMA) was carried out in August - September 2006 that utilized their new 12 meter diameter superpressure balloon and the NCAR driftsonde gondola carrying up to 40 dropsondes and flying at ~50 hPa (~20 km) to study African easterly waves that can result in the genesis of Atlantic Hurricanes.
Terry Hock
Earth Observing Laboratory 3450 Mitchell Lane Boulder, CO 80301
Facility TypeDeployable
LocationNCAR/Earth Observing Laboratory
VariablesDRIFTSONDE: Balloon Type: Either 4 or 5 day Zero Pressure Balloons (e.g. 363 cu meter ~100 mb up to 10,000 cu meter ~10 mb) or a moderate duration Super Pressure Balloon (e.g. 12 meter ~50 mb) that can fly for weeks even months. Scientific Payload: A typical gondola weight with (50 GPS dropsondes) is ~22 kgms. Other scientific instruments could be integrated into the onboard system for flight level measurements. Altitude: Depends on the mission and type balloon. Duration: Depends on the mission and type of balloon with a Zero Pressure Balloon 4 to 5 days typical can go up to ~7 days; with a Super Pressure Balloon week(s) or up to a month or more. With a duration longer than about a week a solar panel/rechargeable battery system must be used. Launch Site Requirements: Some type of shelter for protection during the inflation of the balloon (e.g. hangar), reasonably flat smooth area for launch (e.g. apron in front od hangar), low wind speed (<10 knots) during balloon launch. Launch Crew: Depends on balloon size (typical ~4). Data System: On board Micro-Computer for control, data processing and storage. The onboard data system includes GPS for balloon position as well as flight level wind speed and direction. The onboard system can also measure flight level pressure, temperature and humidity. Communications System: Iridium two-way data link. Up-link commands, downlink data including flight level and dropsonde data.
Archive Data AvailabilityFlight Level: Pressure, Temperature, Humidity, Winds and Balloon Position Dropsonde Data: Pressure, Temperature, Humidity, Winds, Altitude, and Fall Rate.
N/A as of Aug 2009
3 Sep 2009 13:47